Older versions of WordPress used Akismet -trunk as an external. So for active Akismet plugin development we created a -dev directory, to avoid any accidental breakage.

Current versions of WordPress use a release tag of the Akismet plugin as an external. With that change there isn’t much point in having a -dev for the Akismet WP plugin. This is a heads up for anyone still using Akismet -trunk as an external that it will be used for current development work again. If you don’t want to get those changes you should switch your external to the current release tag (2.5.3):